OK, I've been trying to install 2.2.5 on a Compaq Contura 4/25 laptop with
20MB of RAM, and I think I've found the problem. When the machine had 8MB
installed, everything was fine, but when I installed the upgrade to 20MB,
the kernel just crashes. At first I tought I had bad RAM, but a replacement
exhibited the same behavior and passed Compaq's diagnostic.
After a lengthy binary search process on the right value for option MAXMEM,
I've found that the largest value I can use is MAXMEM=(15*1024+768). There's
something evil going on in that 256K just beneath the 16MB address point,
and whenever I try to use it, the system freezes. I suspect Compaq is
remapping the ROM into that space, but I can only say "suspect" since
Compaq's technical support is brain dead and useless and cannot confirm or
deny my hypothesis.
Sadly, there is no way to turn that remapping off in the BIOS setup.
So, assuming that is the problem, is there a way to direct the 2.2.5 kernel
to skip that 256K chunk and still access the RAM above the 16MB point? It
bugs me that I have 4MB sitting up there that I can't get to. I know it
isn't FreeBSD's fault...I'm just hoping for a workaround.
Any help, as always, will be greatly appreciated!
OUR WEB SITE IS UP! Check out http://www.enteract.com/~good